The Effect Of Temperature On Body Size

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Body Size The effect of temperature on body size in Odonata has been relatively under-studied, which is odd considering how studies of other organisms have shown a tightly linked relationship between the two, with body size reducing the higher temperatures get. In fact, one of the most significant studies for temperatures relationship to body size in Odonata was actually a study designed to find the relationship between latitudes and body size. It was the first large-scale study done on latitude and body size, published by Johansson in 2003. However, since latitude and temperature are so closely related, Johansson also recorded temperatures effect in order to isolate a possible direct effect of latitude, or possibly find a response from…show more content…
This method was used instead of weight because the size of exoskeleton reflects weight at emergence, and actual weight measurements could be less accurate due to differences in feeding. The mean temperature of July and January was also recorded at the nearest meteorogical station to relate to body size. For statistical analysis the data was separated by sex due to the difference in size among them and a Principle Component Analysis (PCA) was used to reduce the number of variables that could affect relationship between latitude and body size. To find support for the saw-tooth pattern a distance weight least square (DWLS) fitting was applied to the data. The results for both latitude and temperature showed a U-shaped relationship with body size, which was expected seeing as temperature is generally lower at higher latitudes. A linear regression model showed in both males and females a significant relationship between the trend of larger body size in higher latitudes, and the same relationship with lower temperatures, however in July it was not as pronounced. While it was not the purpose of the study, it provided solid evidence for decreased body size in higher temperatures. An important study on body size was done recently by Hassal in 2013, in which he observed the effects of temperature, latitude, and seasonal effects (combination of temperature and time stress) in the
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